Heart Rate Zone Calculator
Find your five training zones from max heart rate — and the Karvonen version.
The Heart Rate Zone Calculator maps your five training zones from your estimated maximum heart rate (220 minus age is the common formula) and, when you add a resting heart rate, recalculates them with the Karvonen method for a more personalized result.
The zones run from very light (50–60% of max) through the aerobic sweet spot trainers call Zone 2, up to maximum efforts at 90–100%. Knowing your zones turns vague advice into numbers: most base training belongs in Zone 2, tempo work in Zone 3–4, and intervals touch Zone 5.
The age-based max estimate has about ±10 bpm of natural variation; the Karvonen adjustment factors in your resting rate, making zones more accurate for fitter individuals. Educational estimate — a lab or field test gives your true max.
Estimated max heart rate
190 bpm
220 − age (common estimate)
Percentages of max HR; the Karvonen figure (resting-rate adjusted) is shown when a resting rate is entered. Zone 2 builds aerobic base, zones 4–5 push lactate threshold.
How to use the Heart Rate Zone Calculator
- Enter your age.
- Optionally enter your resting heart rate (measured on waking).
- Read your estimated max heart rate.
- See all five zones with bpm ranges.
- When a resting rate is entered, Karvonen-adjusted ranges appear alongside.
Frequently asked questions
How do I calculate my max heart rate?
The standard estimate is 220 minus age: a 40-year-old has an estimated max of 180 bpm. True max is measured with a maximal-effort field or lab test — the estimate is fine for zone planning for most recreational athletes.
What is Zone 2 training?
Zone 2 is roughly 60–70% of max heart rate — the 'conversational' intensity that builds aerobic base and fat oxidation. Most runners and cyclists do the bulk of their training here; this calculator shows your exact Zone 2 range.
What is the Karvonen formula?
Karvonen zones use heart-rate reserve (max minus resting): target = resting + % × (max − resting). It shifts zones upward for fit people with low resting rates, which the age-only method underestimates.
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